The BADERC Transgenic Mouse Core is a service facility that will utilize investigator-derived DNA constructs to create founder transgenic mice and investigator-derived targeted ES cell clones to generate gene knockout mice that can be used to address questions relevant to obesity, diabetes and endocrinology research. The BADERC Transgenic Mouse Core is a cooperative member component of the existent, and highly successful, transgenic facility operating at the Beth Israel Deaconess Medical Center. In addition to the services listed above, the Core will also perform cryopreservation of mutant mouse lines as well as rederivation, as needed. Finally, the Core will provide consultation to BADERC investigators in all aspects of transgenic and gene knockout mice.